Gripper for a drill rod handling apparatus

ABSTRACT

An improved gripper insures that the addition or removal of individual drill rods from the drill column of an earth boring machine will be carried out in a safe and expedient manner. A drill rod handling apparatus including an arm means is positioned to move individual drill rods into and out of the uppermost position in the drill column of the drilling system. An improved gripper is connected to the arm means and adapted to grasp and retain an individual drill rod as it is being moved into and out of the drill column. The gripper includes a fixed gripping means connected to the arm means for receiving the drill rod and a slidable gripping means slidable relatively to the fixed gripping means for cooperating with the fixed gripping means to retain the drill rod. The slidable gripping means includes a tapered surface for contacting the drill rod and the taper angle of the tapered surface is within the range of 7.5* to 45*.

[ Nov. 20, 1973 United States Patent [1 1 Arrington GRIPPER FOR A DRILL ROD HANDLING Primary ExaminerRobert G. Sheridan Assistant ExaminerFrank E. Werner Att0rneyRobert W. Mayer et a].

APPARATUS [76] Inventor:

Thomas Lonnie Arrington, Beaumont, Tex.

Mar. 20, 1972 Appl. No.: 236,002

[57] ABSTRACT An improved gripper insures that the addition or re- [22] Filed:

moval of individual drill rods from the drill column of an earth boring machine will be carried out in a safe and expedient manner. A drill rod handling apparatus [52] :4: g i including an arm means is positioned to move individ- I t Cl l E 1b 14 ual drill rods into and out of the uppermost position in n 19/ the drill column of the drilling System An improved [58] Field of Search....................... 175/85; 214/25, d t d d 214/1 1BC;294/88 87.26 gripper 1S connecte o the arm means an a apted to grasp and retain an individual drill rod as it is being moved into and out of the drill column. The gripper [56] References Cited includes a fixed gripping means connected to the arm UNITED STATES PATENTS means for receiving the drill rod and a slidable gripping means slidable relatively to the fixed gripping means for cooperating with the fixed gripping means to retain the drill rod. The slidable gripping means includes a tapered surface for contacting the drill rod and the taper angle of the tapered surface is within the range of 75 to 45".

FOREIGN PATENTS OR APPLICATIONS 1,068,204 5/1967 Great 294/103 12 Claims, 4 Drawing Figures PAIENIEDmvzo ms SHEET 2 BF 3 GRIPPER FOR A DRILL ROI) HANDLING APPARATUS BACKGROUND OF THE INVENTION The present invention relates to the art of earth boring and, more particularly, to an improved gripper for a drill rod handling apparatus.

During an earth boring operation, it is necessary to add individual drill rods to the drill column of the earth boring system as the length of the column is increased and to remove individual drill rods from the drill column as the length of the drill column is shortened. Each individual drill rod must be lifted from a position near the earth boring machine, positioned in line with the drill column, connected to the drive head of the earth boring machine and connected to the first drill rod of the drill column. It is often necessary to change drill bits during the earth boring operation and a substantial number of drill rods must be handled during the changing of the drill bit. The earth boring operation may be conducted either downward or upward and the earth boring operation may be conducted at an inclined angle.

Various systems have been provided for handling drill rods during an earth boring operation. In general, the systems include arm means for moving a drill rod into and out of position in the earth boring machine with gripping means connected to the arm means for gripping an individual drill rod. The gripping means are generally actuated by an external power source. This has, on occasion, resulted in drill rods being dropped upon failure of the external power source. The gripping means would release the drill rod allowing the drill rod to fall in a haphazard manner in the vicinity of the earth boring machine. The drill rods are heavy and a serious hazard to personnel and damage to equipment can result.

BRIEF DESCRIPTION OF THE PRIOR ART An apparatus for handling pipe is shown in U. S. Pat. No. 3,446,284 to N. D. Dyer et al., patented May 27, 1969. The apparatus includes a frame that is connected with an earth boring machine by a pivot and a double acting hydraulic cylinder that is also pivotally connected with the earth boring machine. The cylinder includes a piston that is pivotally connected with the frame of the earth boring machine so that relatively telescoping movement between the piston and the cylinder pivots the frame about the pivotal connection with the earth boring machine. A pair of spaced sets of pipe gripping members are carried by the frame.

In U. S. Pat. No. 3,460,638 to S. C. Millsapps, Jr., patented Aug. 12, 1969, a raise drilling system is shown that includes a pipe handling apparatus. The pipe handling apparatus includes a pipe load arm connected to the raise drill at its lower end for pivotal movement. Means are provided for moving the pipe load arm and the means include a hydraulic cylinder having a piston rod connected to the lower side of the pipe load arm and the cylinder body connected to the base of the raise drill. Two pair of gripper fingers are pivotally connected to the pipe load arm and are operated by means of air cylinders.

In U. S. Pat. No. 3,272,038 to W. M. Burstall, patented Sept. 13, 1966, a gripping means in combination with a tool for handling pipe is shown. The gripping means includes a pair of jaws pivotally connected to a handle. A latch is adapted to hold the jaws in engagement with the pipe being handled.

In U. S. Pat. No. 2,829,783 to L. Blagg, patented Apr. 8, 1958, a device for positioning a section of drill pipe in a drilling derrick is shown. The device includes a pair of arms which form a V-shaped opening for receiving the section of pipe to be positioned. A latching member is connected to one of the arms by a pivot and a power cylinder and piston actuate the latching member to close the outer end of the V.

In U. S. Pat. No. 3,177,944 to R. N. Knights, patented Apr. 13, 1965, a racking mechanism for earth boring equipment is shown. The racking mechanism includes a plate having a fixed jaw and a movable jaw mounted thereon by a pivot. A hydraulic jack is pivotally interposed between the plate and the movable jaw to turn the movable jaw and grip a drill rod pipe length.

In U. S. Pat. No. 3,270,823 to A. A. Buehler, patented Sept. 6, 1966, a drill pipe handling apparatus is shown. The apparatus includes a pair of movable jaws that contact and grip a second of drill pipe. The movable jaws are actuated by a piston.

In U. S. Pat. No. 3,145,786 to J. D. ONeill et al., patented Aug. 25, 1964, a portable drill rig is shown. The portable drill rig includes a transfer arm including a jaw structure for gripping the pipe. The jaw structure in cludes a pair of movable jaws actuated by a cylinder.

SUMMARY OF THE INVENTION The present invention provides a gripper that will reduce the dangers resulting from the dropping of a drill rod. The gripper is positioned on the arm means of a drill rod handling apparatus. The arm means is adapted to move individual drill rods into and out of the first position in the drill column of an earth boring system. The gripper includes a fixed gripping means connected to the arm means for receiving a drill rod and a slidable gripping means, slidable relative to the fixed gripping means, for cooperating with the fixed gripping means and retaining the drill rod.

It is therefore an object of the present invention to provide an improved gripper for an earth boring machine drill rod handling apparatus.

It is a further object of the present invention to provide a gripper for a drill rod handling apparatus that will reduce the hazard to personnel created by the dropping of a drill rod.

It is a still further object of the present invention to provide a simple and reliable gripper with few moving parts.

The above and other objects and advantages will become apparent from a consideration of the following detailed description of the invention when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 11 is a view in perspective of an earth boring machine including a gripper constructed in accordance with the present invention connected to the drill rod handling apparatus of the earth boring machine.

FIG. 2 is a top view of the gripper shown in FIG. 1.

FIG. 3 shows the taper surface of the gripper.

FIG. 4 is another embodiment of a gripper constructed in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings and in particular to FIG. 1, an earth boring machine generally indicated by the reference numeral lit) is shown anchored to the ground by base elements l1 and i2. A support column 13 is connected to the base elements ill and 32 by a pair of hinges l4 and 15 that allow the support column 13 to pivot. A brace 36 extends between the support column 13 and a frame connecting the base elements 11 and 12. it can be appreciated that the length of the brace 16 determines the angle the support column 13 makes with the horizontal and consequently the drilling angle. it is therefore possible to adjust the support column angle and the drilling angle for various drilling operations by replacing brace 16 with a brace of a different length or by adjusting the length of brace 16.

A carriage l7 is mounted for travel along the support column 13. A pair of thrust means 18 and 1% are provided to move the carriage 17 along the support col umn l3. Each of the thrust means id and 19 include a series of three hydraulic cylinders with one of the cylinders directed downward and two of the cylinders di rected upward. A plate 20 is affixed to hinges l4 and i and support column 13. The thrust means lid and E) are connected between the plate 26 and the carriage 17. A power unit it is connected to the carriage l7 and adapted to provide rotary drilling forces to a rotary drill column 22. The rotary drilling forces are transmitted from the power unit 21 to the drill column by a drill rod chuck 23. A slip table 24 cooperates with the plate 2b to retain the drill column 22 during the make up and break out of drill rods. 7

A drill rod handling apparatus generally designated by the reference numeral 25 is connected to the earth boring machine for moving individual sections of drill rod such as drill rod as into and out of line with the drill column 22. A base plate 27 is firmly affixed to the earth boring machine Hill. A first arm 2% is rotatably mounted in the base plate .27. A second arm 29 projects from the first arm 28. A hydraulic cylinder 3@ is connected between the earth boring machine ill) and a plate 31 that extends from the first arm 28-. Actuation of the hydraulic cylinder 3% causes the first arm 28 to rotate thereby moving the drill rod 26 into line with. the drill column 22 and the drill rod chuck 23. A fixed gripping means 32 is affixed to arm 29 for receiving drill rod 26. A slidable gripping means 33 is slidably positioned relative to said fixed gripping means 32 for cooperating with said fixed gripping means 32 to retain the drill rod 26 when the drill rod 26 is being moved.

Referring now to H6. 2, a top view of the gripper of FIG. 1 is shown. The fixed gripping means 32 is connected to arm 29 and adapted to receive the drill rod 26. The drill rod 32 includes a curved surface 34 that contacts at least a portion of one radial quadrant of the outer surface of the drill rod 26. The surface 34, as shown, contacts almost two full quadrants of th\. outer surface 35 of the drill rod 26. However, it is to be un derstood that less surface could be contacted. The slidable gripping means 33 is positioned to slide in a bore 36 that extends through the fixed gripping means 32. The slidable gripping means 33 includes a movable gripping element 3'? with a tapered gripping surface 38. When the movable gripping element 37 is in an extended position, the tapered gripping surface 38 con-- tacts the outer surface 35 of drill rod 2s at a position spaced from the area of contact of surface 34 with surface 35. The movable gripping element 37 is connected to a double acting hydraulic thrust cylinder 39., The

double acting hydraulic thrust cylinder 39 is affixed to the arm 29 and the movable piston 40 of the double acting hydraulic thrust cylinder 39 is connected to the movable gripping element 37.

Referring now to FIG. 3, a portion of the movable gripping element 37 is shown with the tapered gripping surface 38 in contact with the outer surface 35 of the drill rod 26. The tapered gripping surface 38 has a taper angle a with the center line of the movable gripping element. The gripping forces are transmitted at an angle 0 to the central axis of the movable gripping element 3?. The tapered gripping surface 38 will, of course, be tangent to the outer surface 35 of the drill rod 26 and the sum of angles a and 9 will be 90. The angle a in the embodiment shown in FIGS. 1, 2 and 3 is an angle of l5. A taper angle of less than would create a locking taper and difficulties would be encountered in withdrawing the movable gripping element 37. This would also mean that the movable gripping element 37 would have to move a substantial distance when gripping the drill rod 26. If the taper angle is much greater than 40, the force from the double acting cylinder tends to act directly against the drill rod 26 and push the drill rod 26 against the curved surface of the fixed gripping means 32. It is therefore desirable for the angle a to be within the range of from 75 to 45. in the preferred embodiment of the invention shown in FlGS. l1, 2 and 3, the angle a is approximately 15. With the angle a being IS, the angle 8 is 75.

The structural details of a system constructed in accordance with the present invention having been described, the operation of the system will now be considered in conjunction with a raise drilling operation. During a raise drilling operation, a small pilot hole is drilled to another level of a mine. The small diameter pilot bit is removed from the drill column and a large diameter raise bit is attached. The raise bit is then rotated and moved upward to enlarge the pilot hole to the desired size. During the drilling of the pilot hole, individual drill rods are added to the drill column as the pilot hole extends further and further into the formations. When the small diameter pilot hole is being enlarged into a large diameter hole, individual drill rods must be removed from the drill column as the large diameter bit moves closer to the earth boring machine. For example, when the earth boring machine E0 is being used to drill a small diameter pilot hole, individual drill rod sections such as drill rod 26 must be added to the drill column 22. When the drill rod chuck 23 reaches its lowest posh tion in the earth boring machine it], the first drill rod of the drill column 22 is engaged by the slip table 24. The drill rod chuck 23 is disengaged from the first drill rod and the carriage 17 is moved to the upper position as shown in P26. 1. With the carriage 17 in the upper position, a drill rod 26 is moved into line with the drill column 22 and the drill rod chuck 23. The carriage is then moved downward until the drill rod chuck 23 comes into contact with the upper threaded portion of the drill rod 26. The drill rod chuck 23 is then engaged with the upper portion of the drill rod 26 and the lower portion of the drill rod 26 is engaged with the upper portion of the first drill rod of the drill column 22. The drilling operation is then ready to proceed and drilling continues until it is necessary to add another drill rod wherein the operation just described is repeated. A more detailed explanation of the operation of adding and removing drill rods from the drill column during a raise drilling system is described in U. S. Pat. No. 3,446,284 to N. D. Dyer et al., patented May 27, 1969. It is to be understood that the drilling operation may also be conducted upward into the formations above the earth boring machine it and that the drilling angle of the drilling operation may be inclined.

The operation of the drill rod handling apparatus 25 will now be considered with reference to FIGS. 1, 2 and 3. The fixed gripping means 32 is moved into contact with the drill rod 26. The drill rod 26 may be stored in a rack and contacted by the fixed gripping means 32 or may be physically moved into position relative to the fixed gripping means 32. The double acting hydraulic cylinder 39 is actuated to move the slidable gripping means 33 into contact with the drill rod. The tapered gripping surface 38 contacts the outer surface 35 of the drill rod and locks the drill rod 26 in the drill rod handling apparatus 25. The hydraulic cylinder 36 is actuated to rotate the first arm 28 thereby moving the second arm 29 and the drill rod 26 toward the drill column 22. Once the drill rod 26 is in line with the drill column 22 and the drill rod chuck 23, the carriage 17 is moved downward until the drill rod chuck 23 contacts the threads on the upper end of the drill rod 26. The drill rod chuck 23 is then rotated to engage the drill rod 26. The double acting hydraulic cylinder 29 is then actuated to move the slidable gripping means 33 out of engagement with the outer surface 35 of the drill rod 26. The carriage 17 is moved downward until the lower end of the drill rod 26 contacts the first drill rod of the drill column 22. The drill rod chuck 23 is then rotated causing the drill rod 26 to engage the threads on the upper end of the first drill rod of the drill column 22. The earth boring system is then ready to continue the drilling operation. Drill rods may be removed from the drill column by reversing the operation just described. In the event hydraulic pressure is lost, the drill rod 26 will drop straight down instead of being dropped to the side. This provides a substantial safety advantage because personnel working around the earth boring machine will not be in danger of injury from the dropping of a drill rod. The lower end of the drill rod 26 is usually fairly close to the ground and there is little likelihood that an individual will be between the end of the drill rod 26 and the ground; therefore, the likelihood of injury to personnel is minimal. The upper end of the drill rod 26 will be retained by the gripper even though the drill rod is dropped because the slidable gripping means 33 will remain in a sufficiently projected position to prevent the upper end of the drill rod 26 from falling outward.

Referring now to FIG. 4, another embodiment of the present invention is shown. A first arm 43 is rotatably mounted in a base plate (not shown) adapted to be connected to an earth boring machine. A pair of second arms 42 and 43 project from the first arm 41. A fixed gripping means 44 is connected to arm 43 and a fixed gripping means 45 is connected to arm 42. The fixed gripping means 44 and 45 receive a section of drill rod 46. A slidable gripping means 47 is slidably positioned relative to the fixed gripping means 44 and adapted to cooperate with said fixed gripping means 44 to retain the lower portion of the drill rod 46 when the drill rod 46 is being moved. A slidable gripping means 48 is slidably positioned relative to the fixed gripping means 45 and adapted to cooperate with said fixed gripping means 45 to retain the upper portion of the drill rod 46 when the drill rod 46 is being moved.

The first arm 41 is rotated until the fixed gripping means 44 and 45 contact drill rod 46. The slidable gripping means 47 and 48 are then moved into contact with the drill rod 46. This securely locks the drill rod 46 to the drill rod handling apparatus. The first arm 41 is again rotated thereby moving the second arms 42 and 43 until the drill rod 46 is in line with the drill head of the earth boring machine and the drill string. The drill rod 46 is connected to the earth boring machine and the slidable gripping means 47 and 48 are retracted thereby releasing drill rod 46. The first arm 41 may be again rotated moving the second arms 42 and 43 into position to grasp another section of drill rod. In the event of a drill rod being released by the gripping means, the drill rod 46 will drop straight down thereby minimizing the danger of personnel working around the earth boring machine being injured.

The embodiments of an invention in which an exclusive property or privilege is claimed are defined as fol lows:

l. A drill rod handling apparatus for an earth boring machine wherein the earth boring machine includes drilling means for supplying drilling forces to a drill column and said drill column includes individual drill rods connected together end to end to form said drill column, comprising:

arm means for moving an individual drill rod into and out of line with the drill column;

fixed gripping means connected to said arm means for receiving said drill rod;

slidable gripping means, slidable relative to said fixed gripping means, for cooperating with said fixed gripping means to retain said drill rod, said slidable gripping means including a tapered surface for contacting said drill rod; and

force means connected to said slidable gripping means for selectively sliding said slidable gripping means into contact with said drill rod and forcing said tapered surface into contact with said drill rod to grip and retain said drill rod.

2. The apparatus of claim 1 wherein said force means is a thrust cylinder.

3. The apparatus of claim 2 wherein said tapered surface has a taper angle in the range of from 7.5 to 45.

4. The apparatus of claim 2 wherein said tapered surface has a taper angle in the range of from to 30.

5. The apparatus of claim 2 wherein said tapered surface has a taper angle in the range of from 75 to 20.

6. The apparatus of claim 11 wherein said fixed gripping means includes a curved surface for contacting said drill rod on a portion of at least one quadrant of the surface of said drill rod and said slidable gripping means includes a surface for contacting said drill rod on a portion of one of the other quadrants of the surface of said drill rod.

7. A gripper for a drill rod handling apparatus that will grip and retain a drill rod thereby removably connecting the drill rod to an arm of the drill rod handling apparatus, comprising:

fixed means for receiving the drill rod;

slidable means slidable relative to said fixed means for selectively retaining said drill rod, said slidable means including a tapered surface for contacting said drill rod; and force means connected to said slidable gripping means for selectively sliding said 11. The gripper of claim 8 wherein said tapered sur' face has a taper angle in the range of from 7.5 to 20.

12. The gripper of claim 8 wherein said fixed means includes a curved surface for contacting said drill rod on a portion of at least one quadrant of the surface of said drill rod and said slidable means includes a surface for contacting said drill rod on a portion of one of the other quadrants of the surface of said drill rod.

igylgg UNFLTED ST LTES PATENT OFFICE CEQTHHCATE Q1 CGKRECTIQN Patent No. 773 .188 Dated November 20, 1973 l n fl Thomas Lonnie Arrinrrton It is certified that error appears in the above-identified patentand that said Letters Patent are hereby corrected as shown below:

Page 1, please add -Assignee; Dresserlndust'ries, Inc., Dallas, Tex.--.

Column 2; line 21, second" should be --section--.

Column l, line 22, "HO should be l5--.

Signed and sealed this 9th da ofKiSr- I IWET Attest:

EDNA-RD M.FLET0HER,JR. c. MARSHALL DANN Attesting Officer Commissioner of Patents 

1. A drill rod handling apparatus for an earth boring machine wherein the earth boring machine includes drilling means for supplying drilling forces to a drill column and said drill column includes individual drill rods connected together end to end to form said drill column, comprising: arm means for moving an individual drill rod into and out of line with the drill column; fixed gripping means connected to said arm means for receiving said drill rod; slidable gripping means, slidable relative to said fixed gripping means, for cooperating with said fixed gripping means to retain said drill rod, said slidable gripping means including a tapered surface for contacting said drill rod; and force means connected to said slidable gripping means for selectively sliding said slidable gripping means into contact with said drill rod and forcing said tapered surface into contact with said drill rod to grip and retain said drill rod.
 2. The apparatus of claim 1 wherein said force means is a thrust cylinder.
 3. The apparatus of claim 2 wherein said tapered surface has a taper angle in the range of from 7.5* to 45*.
 4. The apparatus of claim 2 wherein said tapered surface has a taper angle in the range of from 7.5* to 30*.
 5. The apparatus of claim 2 wherein said tapered surface has a taper angle in the range of from 7.5* to 20*.
 6. The apparatus of claim 1 wherein said fixed gripping means includes a curved surface for contacting said drill rod on a portion of at least one quadrant of the surface of said drill rod and said slidable gripping means includes a surface for contacting said drill rod on a portion of one of the other quadrants of the surface of said drill rod.
 7. A gripper for a drill rod handling apparatus that will grip and retain a drill rod thereby removably connecting the drill rod to an arm of the drill rod handling apparatus, comprising: fixed means for receiving the drill rod; slidable means slidable relative to said fixed means for selectively retaining said drill rod, said slidable means including a tapered surface for contacting said drill rod; and force means connected to said slidable gripping means for selectively sliding said slidable gripping means into contact with said drill rod and forcing said tapered surface into contact with said drill rod to grip and retain said drill rod.
 8. The gripper of claim 7 wherein said force means is a thrust cylinder.
 9. The gripper of claim 8 wherein said tapered surface has a taper angle in the range of from 7.5* to 45*.
 10. The gripper of claim 8 wherein said tapered surface has a taper angle in the range of from 7.5* to 30*.
 11. The gripper of claim 8 wherein said tapered surface has a taper angle in the range of from 7.5* to 20*.
 12. The gripper of claim 8 wherein said fixed means includes a curved surface for contacting said drill rod on a portion of at least one quadrant of the surface of said drill rod and said slidable means includes a surface for contacting said drill rod on a portion of one of the other quadrants of the surface of said drill rod. 